In an array substrate of a liquid crystal display device, vias are arranged at many positions. For example, as shown in FIG. 1 and FIG. 2, a via 8 is arranged in a passivation layer 4 above a drain 14 of a thin film transistor, and a pixel electrode 3 is connected to the drain 14 through the via 8. In an array substrate, an alignment layer 5 covering other display structure is further provided for allowing liquid crystal molecules to realize a desired orientation. Due to the presence of the via 8, the alignment layer 5 will be depressed at the position of the via 8, but the via 8 is not used for displaying, so that the depression of the alignment 5 has no influence on the display effect. The array substrate further includes an active region 11, a gate 12, a source 13, a gate insulating layer 2, a base substrate 9 and other known structures, and these known structures will not be described one by one.
The inventor has found out at least the following problems in the prior art: the alignment 5 is formed by curing alignment liquid (e.g., polyimide solution), but the alignment liquid has fluidity, so the alignment liquid around the via 8 will spread into the via 8 before curing or during curing; meanwhile, as the curing continues, the fluidity of the alignment liquid gradually becomes poor (that is, the alignment liquid gradually becomes “sticky”), so the alignment liquid cannot be supplied to the surrounding of the via. As a result, the thickness of the finally formed alignment layer 5 around the via 8 is not uniform, but the positions (e.g., pixel electrode 3) around the via 8 may be used for displaying, so that the non-uniform thickness of the alignment layer 5 will influence displaying and thus reduces the yield and quality of products.